Work & Power Calculator
Work & Power Calculator. Free online calculator with formula, examples and step-by-step guide.
Work and Power Calculator
This calculator determines the mechanical work done by a force and the power required to perform it in a given time, fundamental concepts in physics and engineering.
Work and power formulas
The basic formulas are:
- Work: W = F × d (force times distance)
- Power: P = W / t (work per unit time)
- Alternative power: P = F × v (force times velocity)
Work is measured in joules (J), power in watts (W) and 1 watt = 1 joule/second.
Example 1: pushing an object
Problem: A force of 50 N is applied to move an object 10 m in 5 seconds.
- Work:
- W = 50 × 10 = 500 J.
- Power:
- P = 500 / 5 = 100 W.
Answer: Work = 500 J, Power = 100 W.
Example 2: lifting a load
Problem: Lift 200 kg to 3 m height in 10 seconds.
- Force (weight):
- F = m × g = 200 × 9.81 = 1,962 N.
- Work:
- W = 1,962 × 3 = 5,886 J.
- Power:
- P = 5,886 / 10 = 588.6 W.
Answer: Work = 5,886 J, Power = 588.6 W.
Common uses of work and power calculation
- Sizing motors and machines for specific tasks.
- Computing energy consumption of industrial processes.
- Evaluating athlete performance in strength sports.
- Designing lifting and transport systems.
- Analyzing efficiency of tools and equipment.
- Solving physics problems in education.
Common mistakes with work and power
- Not considering the angle between force and direction of motion.
- Confusing power (W) with work (J).
- Not converting units correctly (horsepower to watts: 1 hp ≈ 745.7 W).
- Forgetting that work is only done when there is displacement.
Pro tip
If the force is not parallel to the displacement, use W = F × d × cos(θ), where θ is the angle between the force and the direction of motion. When θ = 90°, the work is zero.
A watt (W) is the unit of power: 1 W = 1 J/s. It indicates how much energy is transferred per second.
They are measured in the same units (joules). Work is the transfer of energy through a force. They are conceptually equivalent.
1 hp ≈ 745.7 W. Divide watts by 745.7 to get horsepower.
Yes. If the force opposes the motion (like friction), the work is negative because the force removes energy from the system.